1. Technical Field
One or more embodiments relate generally to processing animal hides. More specifically, one or more embodiments relate to systems and methods of processing raw animal hides into leather.
2. Background and Relevant Art
In general, tanning is the process of transforming raw animal hides into leather. More specifically, tanning involves treating animal hides with certain chemicals that prevent the hides from decaying and make the hides more supple and durable. Most often, raw animal hides come from slaughterhouses that slaughter animals to harvest animal meat. However, in other cases raw animal hides may come from other facilities, such as knackeries or tanneries that slaughter and skin various animals for a variety of reasons. Thus, while the vast majority of leather is made from the hides of bovine (e.g., cattle), ovine (e.g., sheep), porcine (e.g., pigs), and caprine (e.g., goats) animals, a wide assortment of leather is also produced from the hides of various other animals, such as deer, bison, buffalo, ostrich, kangaroo, crocodile, alligator, snake, eel, and stingray.
Following removal of the hides from the animals, curing is typically used to prevent decomposition of the raw animal hides before they are subjected to further tanning processes. Examples of curing include treating the raw animal hides with salt (e.g., by wet-salting or brine-curing the hides) or preserving the raw animal hides at a cold temperature (e.g., by packing the hides with ice). Accordingly, in most cases curing facilitates the preservation of the raw animal hides while they are transported from a slaughterhouse to a tannery.
Once received at a tanning facility, the animal hides are usually subjected to various processes that remove non-leather forming substances (e.g., hair and fat) from the hides. Such processes are generally referred to as beamhouse operations. Typically, beamhouse operations may include trimming, soaking, fleshing, unhairing, liming, bating, deliming, and pickling processes. Trimming is performed to remove unwanted or unusable portions of the animal hides. Soaking is used to make the hides more soft and flexible by reintroducing water into the hides that may have been lost due to curing. Fleshing is performed to facilitate the penetration of chemicals into the hides by removing fat and other substances from the hides. Fleshing may also be used to shape the hides to conform to a uniform thickness. Unhairing removes hair and other non-leather forming substances from the hides typically by treating the hides with specific chemicals. Usually, liming is the most common method of unhairing. However, thermal, oxidative, and other chemical methods of hair removal are known, and a mechanical process of unhairing, called scudding, is also sometimes used. Liming is also employed to swell and break up certain tissue fibers in the hides, as well as prepare the collagen in the hides for proper tanning. Bating and deliming usually involves treating the hides with certain enzymes that remove undesirable components of the tissue of the hides, thereby making the hides softer and more stretchy and flexible. Oftentimes, pickling is used to preserve the hides or prepare the hides for tanning by changing the acidity of the hides.
Following the beamhouse operations described above, the animal hides are typically tanned using one of two chemical tanning processes, chrome tanning or vegetable tanning, which create a reaction between collagen fibers of the hides and certain chemical tanning agents. Chrome tanning usually involves treating the hides with chromium, whereas vegetable tanning usually involves treating the hides with vegetable tannins. Other tanning agents may also be used, such as alum, syntans, formaldehyde, glutaraldehyde, and heavy oils. Once chrome tanning or vegetable tanning of the hides is complete, the tanned hides may be processed further before being made into finished leather. Further processing usually involves wringing, grading, splitting, and shaving of the tanned hides. After any further processing is completed, the tanned hides are ordinarily subjected to retanning, coloring, fatliquoring, and finishing processes that generate finished leather from the hides.
Typical tanning systems and methods involve significant amounts of time consuming manual labor. For instance, typical tanning systems and methods include manual unloading, loading, and transporting of animal hides to and from areas of a tanning facility that perform various tanning processes, such as beamhouse operations and chemical tanning processes. For example, tannery workers may manually unload raw animal hides from containers used to transport the hides to the tanning facility. Similarly, tannery workers often manually load animal hides into drums that perform the liming and chemical tanning processes, as well as other machines that aid in carrying out other tanning processes, such as fleshing machines. As a further example, tannery workers may manually transport hides (e.g., using rolling carts) to liming drums, fleshing machines, and chemical tanning drums. Conventional tanning systems may also use manual labor to separate, measure, sort, route, deflesh, and chemically treat the hides at the appropriate time during the tanning process.
Due, at least in part, to the significant amount of manual labor involved, conventional tanning systems have several disadvantages. For example, the manual handling of hides throughout conventional tanning systems is inefficient and time consuming, which increases the expense of a tanning process. For example, the manual unloading, loading, and transporting of hides oftentimes is unpredictable, and therefore contributes to a lack of coordination among various tanning processes in a tanning facility. In particular, workers in a tanning facility may manually unload raw hides from a transportation vehicle at a faster rate than they can manually transport and load the hides into liming drums or chemical tanning drums, resulting in an undesirable buildup of raw animal hides. As an alternative example, workers in a tanning facility may unload hides from a transportation vehicle at a slower rate than they can manually transport and load the hides into liming drums or chemical tanning drums, thereby causing unwanted underutilization of those drums. The lack of coordination and precise control over tanning processes within typical tanning facilities is inefficient and expensive.
Additionally, the manual handling of hides throughout a typical tanning process may often cause damage to the hides. For example, tanning workers may inadvertently damage hides during the manual handling of the hides, causing unwanted nicks, cuts, or scrapes. Oftentimes, damage caused by the manual handling of hides leads to less valuable tanned hides, thereby resulting in a loss in the monetary value of the hides and ultimately reduced profit for the tannery facility operator. Further, such damage also typically leads to tanned hides of inconsistent quality, thereby giving rise to limited uses for the hides and diminished customer satisfaction.
Furthermore, due to relying on manual processes, it is common for conventional tanning facilities to apply the same tanning processes to all hides, regardless of particular hide characteristics. More specifically, it is common to use the same liming and chemical tanning recipes for all hides, despite differences in hide characteristics, such as hide weight, size, or type. Applying the same liming and chemical tanning recipes to all hides typically leads to lower quality tanned hides that may require further manual treatment to become sufficiently tanned into leather. For example, some hides subjected to the same liming and chemical recipes may be “under-tanned” (i.e., insufficiently subjected to the liming and chemical tanning processes) or “over-tanned” (i.e., excessively subjected to the liming and chemical tanning processes). Such “under-tanned” or “over-tanned” hides may receive lower hide grades, resulting in less valuable hides and reduced profits for the tanning facility operator.
Due to conventional tanning facilities not accounting for specific hide characteristics, such facilities often commingle hides of different characteristics. For example, conventional tanning facilities typically commingle heifer, steer, and jumbo type hides and subject these commingled hides to the same tanning processes. In some instances, applying the same tanning processes to commingled hides results in “over-tanned” heifer type hides and “under-tanned” jumbo type hides. For example, a heifer type hide may be more optimally tanned by a first tanning process tailored to heifer hides (e.g., a first liming recipe and a first chemical tanning recipe), whereas a jumbo type hide may be more optimally tanned by a second tanning process tailored to jumbo hides (e.g., a second liming recipe and a second chemical tanning recipe). Thus, the commingling and treating of different types of hides may create inconsistently tanned hides, which ultimately results in a product that is less satisfactory for customers.
Additionally, the manual handling of hides in a tanning facility may make it difficult to trace hides throughout the tanning processes. The inability to sufficiently track hides through a tanning process reduces the ability to identify and troubleshoot problems in a conventional tanning process. Moreover, such a lack of traceability causes further difficulties in optimizing a tanning process. The inability to troubleshoot and optimize a tanning process causes conventional tanning systems to produce lower quality products, often at a higher cost.
Accordingly, there are a number of considerations to be made in processing raw animal hides into leather.